'I would try not to cry in front of his older brothers and fail and they’d ask why.'

The ‘Catastrophe’ actor, 41, and his wife Leah, found out their son had a brain tumour in 2016, shortly before his son’s first birthday. Henry had surgery to remove the tumour and carried on having treatment into 2017, but the cancer returned late last year.

Writing on Medium, Delaney explains he had started writing the post as a book for parents of sick children, but decided to stop writing when he saw his son’s last bad MRI scan.

He shared the emotional essay on Twitter on 18 September with the caption: “I hope this helps.”

Delaney recalls a time he was on a bus on his way to the hospital to visit his son, shortly after he had his brain tumour removed. He reflected on wanting to take Henry on a bus one day and described how tired he felt.

“The front of my head feels like it’s stuffed with hot trash. My chest and throat feel constricted and I’m reminded that while my life is and will remain stressful for the foreseeable future.”

Despite this he explained that he was always excited to go visit his son in hospital and see Henry’s face light up as he walked into the room.

Delaney also talks about the time they first noticed his son was ill, when he vomited at his older brother’s 5th birthday party. He had been feeding him blueberries and wondered if he’d given him too many. But when he carried on being sick, they took him to A&E.

Originally, doctors thought Henry had a UTI and prescribed him antibiotics. But when he continued to be sick and started to lose weight, they knew something was wrong.

“His vomit became the most precious substance in the world to me and I would often start crying whenever he threw up,” Delaney wrote. “I would try not to cry in front of his older brothers and fail and they’d ask why, and I would say it was because I was scared.”

My wife recently walked in on me crying and listening to recordings of him babbling, from before his diagnosis and surgery."

Later, doctors gave Henry an MRI scan and a tumour was confirmed. He had surgery to remove the tumour. He also had to have a tracheotomy, which stopped Henry from speaking and damage to his cranial nerves meant he was deaf in one ear. “My wife recently walked in on me crying and listening to recordings of him babbling, from before his diagnosis and surgery,” wrote Delaney.

Delaney went on to explain a time where he had to use his strength to hold his son down on a hospital bed while the nurse and doctor took out his tracheotomy tube, which had broken. The post ended quite abruptly, where Delaney explained he stopped writing so he could focus on spending as much time as possible in the last few months with his son.

“The reason I’m putting this out there now is that the intended audience for this book was to be my fellow parents of very sick children,” he wrote. “They were always so tired and sad, like ghosts, walking the halls of the hospitals, and I wanted them to know someone understood and cared. I’d still like them to know that, so here these few pages are, for them. Or for you.”

Delaney and his wife Leah are currently expecting their fourth child together.